External rear view mirrors of this type are used in a wide variety of designs in motor vehicle construction. In addition to the glass subassembly, in the mirror surface of which the driver can observe the traffic behind, these external rear view mirrors comprise at least one electrical function element. Electrical function elements are all subassemblies which need to be supplied with electrical voltage from the vehicle power supply, such as the vehicle battery or vehicle ignition system which is typically at a nominal of 12 Volts or in the future 42 Volts, in order to function correctly. Also electro-optic reflective elements such as an electro-chromatic reflective element in the external rear view mirror are typically electrically connected to the vehicle interior mirror (or to another vehicular component) requiring further wiring connection to the vehicle cabin. Particularly frequently, but by no means exclusively, electrical adjustment drives for adjusting the glass subassembly and/or lighting devices and/or folding drives and/or heating elements are fitted in external rear view mirrors of this type. Further electrical function elements which can be built into the external rear view mirror are signal devices, such as indicators, brake lights, side lights and parking lights. Also included under the heading of electrical function elements in the sense of the invention are sensors which are fitted into the external rear view mirrors, such as thermal sensors, proximity sensors, toll-booth transducers, blind-spot detectors, car phone antennae, radar sensors, radio receivers and/or GPS antennae systems.
For the mechanical securing of the individual electrical function elements in the external rear view mirror, the latter comprises at least one support element. The support element is in turn directly or indirectly connected to a mirror base secured to the vehicle body, for example via a swivel or tilting joint, which may comprise a powerfold joint as is known in the art.
In order to supply the electrical function elements in the external rear view mirror, sets of cables are guided into the mirror interior, so that the function elements can be connected via plug connections to the electrical vehicle power supply of the motor vehicle.
A disadvantage of the known cabling of external rear view mirrors is that the required cable sets need to be predominantly laid by hand with a high assembly outlay. In addition, the cable sets and plug connections need to be protected, at high cost, against malfunctioning caused by wear, for example as a result of vibrations and friction, or by the penetration of moisture and leakage water.